About JD Kemp
I Build the Systems a Business Actually Runs On
One engineer. I write production software for local service businesses, and I embed with companies that need someone who can learn a customer's world fast and ship into it.
Achieve Business
✦ Growth
Meet the Founder
JD Kemp
Engineer · Owner, Haslett Handyman
I build production software, and I run a home-services business that depends on it. Those are not two careers. The second is why I am any good at the first.
Most people who build software for service businesses have never quoted a job, chased an invoice, or lost a customer to a booking form that did not work. I have done all three, this year, with my own money on the line. It changes what you build.
I work alone on purpose. The person you talk to is the person writing the code, and nothing gets handed to a junior.
Why I do this
Empowering Service Businesses to Reach Their Full Potential
Every local service business deserves software that fits how it actually works, not a platform it has to bend around. Most of them are running on spreadsheets and memory because the alternative was priced for someone bigger.
That is the gap I build into. Not a website — the operational software behind it: how work comes in, how it gets scheduled, and how you get paid without chasing anyone.
How this started
From My Own Business to Yours
It started with my own business, not a business plan.
How I work
What I Refuse to Fake
Results First
If it does not save you time or make you money, I will say so rather than build it.
Plain answers
Published pricing, honest scope, and "you do not need this" when that is the answer.
One person
The person you talk to is the person building it. Nothing gets handed to a junior.
Built it myself first
My own service business runs on software I wrote. I would not sell you something I would not run.
The other half of the work
Forward-deployed engineering
I embed with a company, learn the customer's business fast, and ship the production system that makes the product work in their world.
Every other engineer up for that work has never run a business. I have. So when an AI company sells into trades, home services or clinics, I do not need to learn the customer — I am the customer, and I can build.
The breadth is the job: their auth, their database, their frontend, their deploy, and someone's spreadsheet. Undocumented APIs and data that arrives wrong are the work, not an obstacle to it.
Multi-tenant clinical platform
Many separately branded clinics on one system, patient data isolated by PostgreSQL row-level security rather than by application code, and a swappable clinical-network adapter. 95 TypeScript source files, 29 test files, 36 migrations, four subdomains from one deployment.
Designed and built solo. I own it; it has no live client.
Architecture referenceA public endpoint that fetches arbitrary URLs
The free website audit on this site runs headless Chromium in Lambda against any address a stranger types in. That is an SSRF liability unless the boundary is real: link-local metadata, private ranges, credentials in the URL and non-HTTP schemes are all refused. 14 attack vectors, tested against the deployed endpoint.
Security judgement on an unauthenticated endpoint.
Try the auditAn end-to-end prospecting pipeline
Places API to enrichment to headless audit to scoring to CRM, with idempotent writes, a do-not-contact gate and the compliance rules encoded in the scorer rather than left to whoever runs it. It is how I find my own clients, which is the point — I build tools for myself first.
Ranking runs in code. No model call, so the result is reproducible.
One piece of it, publicWhat I work in
TypeScript and Python · React and React Native · AWS — Lambda, DynamoDB, Postgres/RDS, Cognito, SES, CloudFront · Terraform and CDK · Claude and the evaluation layer that decides whether its answer is good enough to show anyone.
Ready to Work Together?
I will show you how I can help — or tell you honestly that you do not need me.
Get in Touch